The present invention relates to an improved cover for an absorbent personal care product and to the products using such cover. More particularly, the invention relates to the cover for a feminine pad and to pads using such cover. Absorbent pads designed to be worn by humans to absorb bodily fluids, such as urine, menstrual fluid, perspiration, etc., include such articles as disposable diapers, sanitary napkins, panty shields, underarm shields, and incontinence pads. In use, these articles release malodorous vapors. Various compounds, chemicals, mixtures, and like materials (i.e., absorbents such as activated carbon, clay, and zeolites) are known to combat some of these malodorous compounds. Odor absorbents such as activated carbon have been incorporated into sheet materials or fabrics for use in protective articles and clothing. Additionally, because some odor absorbent agents are less effective once they have become wetted, various methods have been employed to minimize the exposure of the odor absorbents to moisture. These methods include: locating the odor absorbents outside of the liquid absorbent layer(s) of the products, protecting the absorbents with liquid impermeable/vapor permeable sheet materials, sandwiching the odor absorbents between two protective layers, hydrophobically coating the absorbents with various compounds to render them liquid impermeable, etc. Particular examples are discussed below.
U.S. Pat. No. 4,732,805 to Maoos discloses an active carbon material that is coated with a gas permeable surface of particulate hydrophobic material which preferably is a fluorocarbon resin such as polytetrafluoroethylene (PTFE). The active carbon can be in the form of a fabric known as charcoal cloth or a felted material, and in such cases the hydrophobic material is present in a range from about 5 to 10% by weight of the active carbon. The coating of fluorocarbon resin protects the activated carbon from absorbing water while allowing the undesirable vapors to permeate through the resin and be adsorbed by the activated carbon. To apply the coating, the activated carbon material is preferably immersed in an aqueous suspension of the hydrophobic material and then dried by applying a flow of air heated to a temperature around 100.degree. C. The hydrophobic material may be present in the suspension in a preferred that the hydrophobic material be present at a concentration of at least 1.5% by weight. When the hydrophobic material is polytetrafluoroethylene, the suspension preferably is stabilized by an anionic wetting agent, but Maoos prefers that no binder or other component is included. The particle size of the hydrophobic material in suspension preferably is between micron and 0.01 micron, with a mean particle size preferably of one tenth of a micron.
U.S. Pat. No. 3,939,838 to Fujinami, et al discloses an article for treating menstrual fluid which employs a cover member forming an enclosure, an absorbent layer positioned within the enclosure for absorbing the menstrual fluid, a water-proofing layer also positioned within the enclosure for preventing the fluid from permeating to the outside of the cover member, and a deodorizer composition such as active carbon and the like located within the enclosure and having the function of absorbing and holding the menstrual fluid and simultaneously removing the odor released from the menstrual fluid. Active carbon, active silica, active alumina, ion exchange resin, chlorophyll, and the like are used as the deodorizers. The deodorizer is contained in sheets that are made of cellulose fiber. The deodorizer sheets can be interposed between the respective absorbent layers and the respective water-proofing layers, or in the absorbent layer and/or in the water-proofing.
U.S. Pat. No. 3,693,622 to Jones discloses waste fluid absorption devices, including sanitary napkins and tampons, comprising a coplanar multiple ply of thin absorbent tissue paper impregnated in selected exterior border areas with non-toxic, waste fluid repellent compositions. Typically, the repellent impregnant can be non-volatile polyfluorocarbon fluids; non-volatile dimethyl polysiloxane fluids; non-volatile hydrocarbon oil fluids; non-volatile fluid long chain fatty acid alkyl esters, and non-volatile mono-, di-, and tri-glyceride esters of long chain fatty acids.
U.S. Pat. No. 4,467,013 to Baldwin discloses non-woven bioactive, water and alcohol-repellent medical fabrics provided with a bioactive finish which is substantive on the fabric and is able to destroy migrating and cross-contaminating bacteria, algae and fungi. Specifically, a process for preparing a water and alcohol repellent, bacteriostatic non-woven medical substrate includes applying a solution of a specific silicone quaternary amine together with a water-repelling fluorocarbon and a wax/resin fluorocarbon extender, to produce the desired repellent surface. The fluorocarbon repellent component is typically a dispersion of fluoropolymer in water.
U.S. Pat. No. 3,068,187 to Bolstad discloses segmented fluorine-containing copolymers useful for imparting repellency to oil and water and resistance to soiling to a variety of substrates. Fibrous, porous and continuous surfaces may be treated with these segmented polymers. The segmented copolymers may be applied as a surface treatment by known methods of coating such as spraying, brushing or impregnation from an aqueous or organic solvent dispersion or an organic solvent solution of the segmented copolymer.
U.S. Pat. No. 3,683,917 to Comerford discloses a product for absorbing and retaining body fluids comprising a cellulosic absorbent body or core, a cellulosic covering, and a biodegradable, water impervious barrier sheet or layer which comprises a water repellent material deposited on a cellulosic tissue. Among such water repellent materials are: various fluorocarbons such as PTFE, CTFE, FEP, etc.; "Scotchguard" Repellents FC-208, FC-210, FC-212, FC-214, etc.; silicones such as Dri-Film 1040, a methyl hydrogen polysiloxane and Dri-Film 1042 and 1043, modified methyl hydrogen polysiloxanes; cationic starch type water repellents such as "Cyansize" (American Cyanamid) and "Aquapel", a ketone dimer emulsified with a cationic starch, sold by Fancourr Co.; etc.
U.S. Pat. No. 4,565,727 to Giolia, et al discloses an air and water vapor permeable, toxic vapor absorptive non-woven fabric material comprising a wet-laid sheet containing fibrillated acrylic fiber, and an activated carbon constituent selected from the group consisting of activated carbon fiber, activated carbon particles, and mixtures of activated carbon fiber and activated carbon particles. The material is produced via the wet-laying process, utilizing fibrillated acrylic fibers as the binder material, whereby the material is prepared by wet-laying the activated carbon constituent and fibrillated acrylic fibers from a water suspension thereof.
U.S. Pat. No. 4,217,386 to Arons, et al discloses a laminated, highly sorbent, active carbon fabric which is permeable to water vapor while sorbing substantial quantities of toxic chemical vapors, and process of making such a laminated fabric. Arons, et al is concerned with the formation of a multilayered, usually five-layered, laminated structure comprising: an inner woven fabric made of yarns of active carbon, produced by carbonizing high polymer yarns forming the fabric and thereafter activating the carbon; two outer layers (webs) of spunbonded non-woven fabric, prepared from continuous filaments of a high polymer; and two intermediate layers (mats), one on each side of the active carbon fabric. The final five layered, laminated fabric structure is produced by superimposing the layers as described above and fusion welding the five layers together over spaced apart areas. The woven active carbon fabric of the invention may be prepared by spinning high polymer yarns of various types, such as regenerated cellulose yarns of various conventionally produced types, polyacrylonitrile yarns, phenol-formaldehyde yarns, pitch yarns, or other suitable high polymer yarns, weaving such yarns into fabrics, carbonizing the fabrics, and activating the carbonized fabrics, all accomplished conventionally.
U.S. Pat. No. 4,459,332 to Giolia discloses an air and water vapor permeable, toxic vapor absorptive fabric material. The toxic vapor absorptive ingredient is activated carbon fiber flocking having deposited in the voids formed therebetween, activated carbon powder. The invention comprises, in superimposed relationship: (a) a first inactive, woven or non-woven fabric; (b) a first air and water vapor permeable adhesive layer having activated carbon fiber flocking positioned on the surface thereof away from the first inactive fabric and activated carbon powder deposited in the voids formed between the flocking; (c) a second air and water vapor permeable adhesive layer and; (d) a second inactive layer of woven or non-woven fabric. The materials which form components (b) and (c) are produced from water vapor and air permeable adhesives preferably in the form of a foam. Component (b) is prepared by first coating the fabric material (a) with the adhesive foam. The side coated with the adhesive is then flocked with the activated carbon fibers. The activated carbon fibers are deposited upon the foam adhesive side of the coated fabric (a) by any known mechanical flocking method, preferably before the adhesive is heat cured. The fiber flocking is usually sprinkled on top of the foam adhesive coating. To the flocked side of the fabric is then added activated carbon powder while a vacuum is applied from the fabric side to draw the powder into the voids between the flocked carbon fibers.
U.S. Pat. No. 3,439,678 to Thomas discloses a plied fabric having high water resistance and comprising at least two layers, each formed from a woven fabric which is resistant to standing water and is air and water vapor permeable. The fabrics are composed of fibers which are hydrophobic in themselves or are composed of fibers which subsequently are rendered hydrophobic by suitable coating means. One type of coating composition deemed especially suitable by Thomas is the fluoro chemical type textile finish which is marketed by Minnesota Mining & Manufacturing Co. (a.k.a. 3M Company) under the SCOTCHGARD.RTM. trademark. The coating composition may be applied by any well known method such as padding, spraying, immersion, or the like.
U.S. Pat. No. 3,995,636 to Murray, et al discloses a catamenial device such as a tampon which comprises a segment of a rapidly re-expandable hydrophilic polymeric foam held in compression by a constraining means. The constraining means comprises a coating material that includes a mixture of sodium bicarbonate and citric acid. The coating material may be provided by the application of a solution to the surface of the foam segment, or by full impregnation. Murray, et al discloses that the restoration of a slightly acidic environment in the vaginal area prevents the undue accumulation of noxious odor and irritation which results from the enzymatic reduction of the uric acid, urea, amino acids and the like to ammonia and volatile amines.
U.S. Pat. No. 4,508,775 to Adiletta discloses a flexible, microporous, hydrophobic and oleophobic film-like composite structure comprising from about 25 to about 75 parts by weight of inorganic reinforcing microfibers, particularly glass, and from about 75 to about 25 parts by weight of a polymeric binding agent, preferably a copolymer of ethylene and vinyl acetate. A treating agent, preferably a fluorinated hydrocarbon, is present in an amount sufficient to render the composite structure hydrophobic and oleophobic. Alternatively, the treating agent may be combined with the microfibers and binding agent in the slurry prior to laydown and formation of the sheet material. The composite structure may be used in combination with a carbon or chemical liner in protective clothing, in which case it may be desirable to protect the carbon liner layer from body perspiration by laminating an abrasion resistant layer of material, such as a non-woven, spun bonded monofilament polyester, to the charcoal liner on the side opposite the composite structure.
U.S. Pat. No. 4,194,041 to Gore. et al discloses a water-proof article that prevents liquid water from penetrating through to undergarments while at the same time permitting moisture vapor to pass out through the article. The article is layered: a microporous hydrophobic outer layer which permits the passage of moisture vapor but resists penetration by liquid water at pressures up to about 345 kiloNewtons per meter squared (kN/M.sup.2); a hydrophilic inner layer permitting the transfer of moisture vapor but preventing surface tension lowering agents such as those contained in perspiration and/or body oils from reaching the hydrophobic layer. Gore, et al discloses that a film of porous, expanded polytetrafluoroethylene, which has been heated above its crystalline melt point after expansion, has been found to be an ideal hydrophobic layer for rainwear applications. These films are highly porous yet the pores are very small in size. The latter fact results in high water entry pressure. Other hydrophobic materials for use in the outer layer include highly crystalline films of expanded PTFE, which have been heated above their crystalline melt point, and films of other microporous hydrophobic polymers such as polypropylene.
U.S. Pat. No. 4,169,187 to Glazar discloses a powder coating composition of epoxy resins obtained by blending two types of epoxy resins with a curing agent. One resin is of the epichlorohydrin-bisphenol-A-type. The other resin is an epichlorohydrin-bisphenol-A modified with an epoxy-novolac. The Glazer patent discloses using the mixture for coating the interior of food and beverage containers and for a lining in hot-water services when finely divided polyvinylidine fluoride powder is added for hydrophobicity.